Question

Which one of the following is not necessarily saved on a context switch between two processes?

• A. General purpose registers
• B. Translation look-aside buffer
• C. Program counter
• D. Stack pointer

Hint:

Only process-specific CPU state is saved during context switching, not hardware cache contents like the TLB.

Answer 1

The Correct Option is B

Step 1: Understanding context switching.
A context switch occurs when the CPU switches from executing one process to another. To resume execution later, the state of the current process must be saved.
Step 2: Identifying what must be saved.
The CPU state includes the program counter, stack pointer, and general-purpose registers, as these are essential to resume the process correctly.
Step 3: Role of the Translation Look-aside Buffer (TLB).
The TLB is a hardware cache used to speed up virtual-to-physical address translation. Its contents are not part of the process state and are often flushed or overwritten during a context switch.
Step 4: Final conclusion.
Therefore, the Translation Look-aside Buffer is not necessarily saved during a context switch.